Sonography of the Rotator Cuff: Comparison of Arm Positions / 대한정형외과학회잡지

ABSTRACT

PURPOSE: To evaluate the objective difference of the shoulder position during ultrasound examination regarding diagnostic value for shoulder lesion, view range and visibility. MATERIALS AND METHODS: A prospective study was performed enrolling 312 patients who underwent diagnostic ultrasonography due to shoulder pain between January 2016 and June 2016. Examination was performed by a single orthopaedic surgeon with 5 years of musculoskeletal ultrasonography experience. Images of the longitudinal and transverse plane of the supraspinatus tendon and the nearby soft tissues (subscapularis and biceps long head tendon, subdeltoid bursa, etc.) were obtained in the three different positions, shoulder extension, modified Crass, and Crass position. The correlation between the demographic data (age, sex and body mass index) and the visual analogue scale (VAS) of the affected shoulder & the capable shoulder position was analyzed. Another orthopaedic independently measured the size of the tear and using classified the image visibility of the supraspinatus, subscapularis, and biceps long head tendon on the short-axis view from the rotator interval into I to III and X. RESULTS: Of the 312 patients, 126 were excluded and total of 186 cases were included in this study. None of the demographic data were related to the possible arm position. However, VAS for pain was the only factor related with the number of possible arm positions during sonography. Kappa agreements for the diagnosis were mostly high of over 0.90. Grades of the short-axis view from the rotator interval in each position were mostly grade II or grade III, which refers to that the anterior portion of supraspinatus tendon, which is the most fragile portion to the tear and it was well-defined regardless of the arm position. The average longitudinal tear sizes were 1.48, 1.52, and 1.61 cm in the shoulder extension, modified Crass (Middleton), and Crass position, respectively. CONCLUSION: Shoulder extension position during ultrasonography examination of shoulder shows similar diagnosis rate of supraspinatus tendon tear or calcific tendinitis compared to modified Crass (Middleton) or Crass position, the two well-known standard positions. It is also a useful position for patients who suffer with severe shoulder pain.